Weld joint

ABSTRACT

A weld joint for a fuel injection nozzle assembly and the like characterized in that axially interfitting tubular parts define therebetween an annular groove or gap of which one side has an axial step radially spaced outwardly from the bottom of the groove and radially spaced inwardly from the radially outer edge of the side of the groove. A metallic filler ring axially spans said groove and is coaxially located by said step to radially outwardly space its inside and outside surfaces respectively from the bottom of said groove and from the radially outer edges of the sides of said groove. The outside surface of the filler ring extends radially outward beyond the outer portions of the sides of the groove. The protruding portion of the weld ring permits fusion welding of the parts without addition of weld filler material. After the parts are welded together, the weld ring is integrally bonded to the adjacent portions of the sides of the groove to form a strong leakprrof joint between said nozzle parts. Another characterizing feature of the weld joint herein is that a flow divider valve or the like contained within the nozzle assembly can be repeatedly serviced or replaced by simply cutting through the filler ring with the point or tip of the tool entering the space between the bottom of the groove and the inside surface of the filler ring thus to permit separation of the nozzle parts where they are axially interfitted without burn up of the tip of the tool and to permit subsequent reassembly and welding of said parts with the filler ring being the only new part required.

United States Patent [191 Mains [54] WELD JOINT [75] Inventor: Robert T.Mains, Euclid, Ohio [58] Field of Search .;....285/286, 21, 22, 27;29/501, 29/498.5, 503, 472.1; 287/189.36 B

[56] References Cited UNITED STATES PATENTS 2,732,229 1/1956 Gaum..285/21 2,792,490 5/1957 Risch et al. 285/22 X 3,026,910 3/1962 Cawkeret a1 285/21 X 2,129,583 9/1938 Johansson ..29/501 X 2,153,287 4/1939Wallace et al. ..29/50l X 2,741,932 4/1956 Whitney et al. ..29/50l XPrimary Examiner-David J. Williamowsky Assistant ExaminerWayne L. SheddAttorney-Oberlin, Maky, Donnelly & Renner [57] ABSTRACT A weld joint fora fuel injection nozzle assembly and [451 Jan. 9, 1973 the likecharacterized in that axially interfitting tubular parts definetherebetween an annular groove or gap of which one side has an axialstep radially spaced outwardly from the bottom of the groove andradially spaced inwardly from the radially outer edge of the side of thegroove. A metallic filler ring axially spans said groove and iscoaxially located by said step to radially outwardly space its insideand outside surfaces respectively from the bottom of said groove andfrom the radially outer edges of the sides of said groove. The outsidesurface of the filler ring extends radially outward beyond the outerportions of the sides of the groove. The protruding portion of the weldring permits fusion welding of the parts without addition of weld fillermaterial. After the parts are welded together, the weld ring isintegrally bonded to the adjacent portions of the sides of the groove toform a strong leakprrof joint between said nozzle parts. Anothercharacterizing feature of the weld joint herein is that a flow dividervalve or the like contained within the nozzle assembly can be repeatedlyserviced or replaced by simply cutting through the filler ring with thepoint or tip of the tool entering the space between the bottom of thegroove and the inside surface of the tiller ring thus to permitseparation of the nozzle parts where they are axially interfittedwithout burn up of the tip of the tool and to permit subsequentreassembly and welding of said parts with the tiller ring being the onlynew part required.

5 Claims, 5 Drawing Figures PAIENTEDJAN 9 I915 3.709.529

INVENTOR,

I AINS- WELD JOINT BACKGROUND OF THE INVENTION It is of course known inthe art of injection nozzle manufacture to provide welded (or brazed)joints between the parts thereof to provide a strong leakproof nozzleassembly, such joints generally comprising telescoped parts which definetherebetween a V- shaped groove or an internal corner into which weldingmetal is deposited. This is, of course, satisfactory insofar asperformance is concerned, but in portions of the nozzle assembly whereinservicing or replacement of parts may be required, the separation of theparts where welded together may, as a practical matter, be impossible ordifficult without affecting re-use of parts because of flow of weldingmetal between interfitting portions of the parts.

Where it may be necessary or desirable to separate nozzle parts whichhave been welded together, it is known from the Cleminshaw et al. U. S.Pat. No. 3,024,045, granted Mar. 6, 1962, to provide a ring ofrefractory material such as carbon, between annular axially spaced endfaces of parts which are threaded together and to weld together theopposed end faces of the parts, the refractory ring constituting abarrier to prevent radial inward flow of the welding metal to beinterengaged threads of the nozzle parts, whereby, when it is desired toseparate the nozzle parts, the weld metal may be cut down to the outsidediameter of the refractory ring.

SUMMARY OF THE INVENTION In contradistinction to known welded joints ofthe type just described, in the present weld joint the axiallyinterfitting nozzle parts have a metallic filler ring in the annulargroove or gap which is defined between the parts. The outside surface ofthe filler ring extends radially outward beyond the outer portions ofthe sides of the groove. The protruding portion of the weld ring permitsfusion welding of the parts without addition of weld filler material.After the parts are welded together, the weld ring is integrally bondedto the adjacent portions of the sides of the groove to form a strongIeakproofjoint between said nozzle parts. In addition, the tiller ringis radially spaced from the bottom of the groove so that when the partsare to be separated the tip of the cutting ,tool will, in cuttingthrough the filler ring, enter the annular space between the innersurface of the tiller ring and the bottom of the groove, whereby tooltip burn up is prevented.

As a further feature of this invention the telescoped or threadedlyengaged portions of the nozzle parts are axially spaced from the weldarea and are radially between the bottom of the groove and the insidediameter of the filler ring so that these portions will not be bonded bythe fusion weld and therefore, the nozzle parts may readily be separatedupon cutting through the filler ring.

Yet another characterizing feature of this invention is that one of thesides of said groove or gap defined between the welded together parts isformed with an axial step which is engaged by the inner surface of thefiller ring thus to coaxially locate the latter in said groove with itsouter surface outward with respect to the remaining outwardly extendingportions of the sides of the groove and with its inner surface radiallyspaced outwardly from the bottom of the groove. The axially interfittingnozzle parts also have interengaged radially overlapping surfaces whichpredeterminedly locate BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sideelevation view of a dual orifice fuel injection nozzle having a fuelinlet port at one end, a dual orifice injection nozzle at the other end,and a flow divider valve between the ends to control flow of fuel to thesecondary orifice of the nozzle, the housing having a primary fuelpassage through which fuel from the inlet port flows through the primaryorifice of the nozzle;

FIG. 2 is a much enlarged fragmentary radial crosssection view of thejoint herein between the fuel inlet connector and the nozzle housingshowing the metal filler ring interposed between axially spaced apartannular end faces of the connector and housing respectively;

FIG. 3 is a view similar to FIG. 2 except showing the completed fusionweld joint with the filler ring integrally bonded to the connector andhousing;

FIG. 4 is a view similar to FIGS. 2 and 3 except showing how the weldedjoint may be cut apart with the tip of the cutting tool disposed in theinternal annular space between the connector and housing; and

FIG. 5 is an enlarged cross-section view of a weld joint between thenozzle housing and the secondary orifice body member which has threadedengagement with the nozzle housing.

DETAILED DESCRIPTION OF THE INVENTION The nozzle assembly 1 herein shownfor purposes of illustration comprises a nozzle housing 2 having weldedat 3 to its upper end a fuel inlet connector 4 and having welded at 5 toits lower end a dual orifice fuel injection nozzle 6. Between theconnector 4 and the housing 2 is a flow divider or variable area valve(not shown) around which fuel flows through a primary passage whichleads to the primary orifice of the nozzle 6 and through which the flowof fuel from the connector 4 is controlled for flow through a secondarypassage to the secondary orifice of the nozzle 6. For an example of thegeneral type of flow divider which may be contained within the housing 2between the connector 4 and housing 2, reference may be had to thepatent to Davies et al. U.S. Pat. No. 3,022,954, dated Feb. 27, 1962. Asan example of a dual orifice nozzle 6, reference may be had to theaforesaid Cleminshaw et al. U.S. Pat. No. 3,024,045, granted Mar. 6,1962, the nozzle 6 herein being of somewhat modified construction ashereinafter set forth.

Referring now in detail to the welded joint 3 between the connector 4and the housing 2, the upper end of the housing is provided with achamfered counterbore 7 which provides a stop shoulder 8 engaged by theend of the connector 4 which has a cylindrical portion 9 telescopedwithin said counterbore 7. As shown, the annular end face of the housing2 is axially spaced and radially outwardly spaced from the telescopedportions 9 and 7 of the connector 4 and housing 2.

The connector 4 has a stepped annular face 11 of which the outer annularportion is axially spaced from and opposite the annular end face 10 ofthe housing 2, the axial spacing being determined by engagement of theconnector 4 with the stop shoulder 8 in the housing 2. The inner portionof the end face 11 constitutes one side of a peripheral groove which isof diameter less than the diameter of the counterbore 7 and cylindricalportion 9. The other side of the peripheral groove is beveled as shownto meet the cylindrical portion 9 at about the same place that thechamfer meets the counterbore 7.

Between the opposed spaced apart annular end faces 10 and 11 and locatedby the axial step 12 in coaxial relation between the connector 4 andhousing 2 is a filler ring 14 of metal the same as or similar to that ofthe connector 4 and housing 2, for example, No. 347 stainless steel.Said filler ring 14 has an outside diameter greater than the outsidediameter of the annular end faces 10 and 11 and is of axial length fromsay, 0.00l to 0.006 inch less than the axial distance between said endfaces 10 and 11.

When joint 3 is fusion welded as shown in FIG. 3 with the molten metalbridging the gap between said end faces 10 and 11 all but the innerportion of the tiller ring 14 becomes integrally welded to the connector4, and housing 2 to form a strong leakproofjoint. ln welding the joint 3the amount of weld penetration may be varied but it is preferred thatthe radially inner portions of the ends of the tiller ring 14 not bewelded to the juxtaposed portions of the end faces 10 and 11. However,even if the weld 3 does penetrate to the inside diameter of the fillerring 14, the weld metal is yet isolated from the interfittingcylindrical surfaces 7 and 9 which are axially and radially spaced fromthe weld joint 3.

In order to separate the connector 4 and housing 2, a tool T as shown inFIG. 4 may be employed, and when the tip of the tool T breaks into theannular space 15 within the inner surface of the filler ring 14 therewill be no burn up of the tool tip or nozzle parts 2 or 4. When the toolT has penetrated the filler ring 14 the connector 4 and housing 2 mayreadily be separated for servicing or replacement of the flow dividertherewithin. if desired, the tool T may be provided with side cuttingedges as shown to conform with the initial formation of the annular endfaces 10 and 11 so that the housing 2 and connector 4 may be rewelded,using a new filler ring 14.

The weld joint 5 between the lower end of the housing 2 and the dualorifice nozzle 6 is generally of the same type as just described exceptthat the secondary orifice body 16 has screw threaded engagement withthe housing 2, the counterbore 17 of the secondary orifice body 16 beinglarger than the major diameter of the threads and the groove 18 in thehousing 2 being smaller than the minor diameter of the threads, thusagain to axially and radially space the axially interfitting portions ofthe housing and body parts 2 and 16 from the weld joint 5. In thisexample, the primary orifice body 19 is clamped between the shoulder 20of the secondary orifice body 16 and the end of the housing 2, thus tolocate the annular end face 21 of the secondary body 16 in spacedrelation with respect to the stepped annular end face 23 of the housing2 so that initially the filler ring 24 will be loosely disposed betweensaid end faces with a clearance of say, from 0.00l to 0.006 inch.

I, therefore, particularly point out and distinctly claim as myinvention:

1. A weld joint between axially interfitting inner and outer parts of afuel injection nozzle assembly of which the outer part terminates in anannular end wall and of which the inner part has a peripheral groovehaving a bottom wall of diameter less than the inside diameter of saidannular end wall and having a side wall of which the radially outerportion faces, and is axially spaced from, said annular end wall; and ametallic filler ring between said side and end walls of inside diametergreater than the diameter of said bottom wall fusion welded to theradially outer portion of said side wall and to said annular end wall.

2. The weld joint of claim 1 wherein said filler ring is fusion weldedto said side wall and annular end wall only at diameters greater thanthe inside diameter of said annular end wall; the ends of said fillerring radially inward of said fusion welds being in close proximity tosaid side wall and to said annular end wall.

3. The weld joint of claim 1 wherein said side wall has a cylindricalstep on which the inside diameter of said filler ring is piloted tolocate said filler ring coaxially between said inner and outer parts.

4. The weld joint of claim 3 wherein said cylindrical step is ofdiameter substantially equal to the inside diameter of said tiller ringand to the inside diameter of said annular end wall; said filler ringbeing fusion welded to said side wall and to said annular end wall onlyat diameters greater than the diameter of said cylindrical step andgreater than the inside diameter of said annular end wall. V

5. The weld joint of claim 4 wherein said filler ring is of outsidediameter greater than the outside diameters of said side wall and saidannular end wall and forms a rounded weld head between said side walland said annular end wall.

a a a: k

1. A weld joint between axially interfitting inner and outer parts of afuel injection nozzle assembly of which the outer part terminates in anannular end wall and of which the inner part has a peripheral groovehaving a bottom wall of diameter less than the inside diameter of saidannular end wall and having a side wall of which the radially outerportion faces, and is axially spaced from, said annular end wall; and ametallic filler ring between said side and end walls of inside diametergreater than the diameter of said bottom wall fusion welded to theradially outer portion of said side wall and to said annular end wall.2. The weld joint of claim 1 wherein said filler ring is fusion weldedto said side wall and annular end wall only at diameters greater thanthe inside diameter of said annular end wall; the ends of said fillerring radially inward of said fusion welds being in close proximity tosaid side wall and to said annular end wall.
 3. The weld joint of claim1 wherein said side wall has a cylindrical step on which the insidediameter of said filler ring is piloted to locate said filler ringcoaxially between said inner and outer parts.
 4. The weld joint of claim3 wherein said cylindrical step is of diameter substantially equal tothe inside diameter of said filler ring and to the inside diameter ofsaid annular end wall; said filler ring being fusion welded to said sidewall and to said annular end wall only at diameters greater than thediameter of said cylindrical step and greater than the inside diameterof said annular end wall.
 5. The weld joint of claim 4 wherein saidfiller ring is of outside diameter greater than the outside diameters ofsaid side wall and said annular end wall and forms a rounded weld beadbetween said side wall and said annular end wall.